May 18 (UPI) — Authorities said Sunday night that officers arrested three teenagers, ending a weekend shooting spree through southern Austin that left four people wounded, including one critically.

The shootings began Saturday afternoon, with the first calls to police recorded at about 3:45 p.m. CDT. A shelter-in-place order was issued amid the shootings and was lifted shortly before 4:30 p.m. Sunday.

At least 12 separate shootings, mostly in south Austin, were recorded in the crime spree, according to authorities, who said at least two separate fire stations were struck, as were several buildings and homes.

Authorities had been searching Sunday for a stolen white Kia in connection with the shootings. When police pulled it over, three people exited the vehicle and ran. Officers pursued and arrested two suspects — identified as a 15-year-old and a 17-year-old — at the scene, authorities said.

The Manor Police Department announced later Sunday that the third suspect, identified as a Hispanic male in his mid-to-late teens, had been apprehended.

Austin Police Chief Lisa Davis told reporters during a press conference held Sunday night prior to the third arrest that police had been searching for the 15-year-old and 17-year-old and were unsure of the third suspect’s involvement.

Davis described the gunmen as firing indiscriminately from a stolen vehicle that would be abandoned, followed by the theft of another vehicle. More than four vehicles were stolen during the spree, she said.

“And so a motive? I don’t know what a motive is. I don’t know what motive would drive anybody to come and drive around senselessly in the city and in multiple parts of the city shooting,” Davis said.

The investigation began when police were notified of a stolen vehicle from an apartment complex, followed by the alleged theft of a firearm by the 15-year-old from a gun store, Davis said. The 17-year-old was also wanted in connection with an earlier firearm theft from the same store, she said.

“At that point, we were not aware that these two cases were connected. What transpired after that was an estimated of 20 service calls related to these individuals, predominantly in south and east areas of Austin,” she said.

The identities of the victims have not been disclosed.

Davis said a woman was shot from a moving vehicle as she was speaking to another person on Saturday. On Sunday, a man was shot in the back while walking his dog.

All four victims, three with non-life-threatening injuries, were transported to local trauma centers, authorities said.